1. Field of the Invention
The present invention includes a perforated heat sink. More particularly, the present invention includes a compact heat sink having a plurality of holes within a substrate to thermally conduct heat away from a heat source. Most particularly, the holes within the compact heat sink increase the surface area of the substrate for dissipating heat by a factor of two from the substrate without the holes.
2. Brief Description of the Related Art
Types of known thermal management technologies include thermoelectric conduction (TEC), heat pipes, and extruded/bonded fin heat sinks.
Thermoelectric conduction uses DC electricity inside an active cooling device, typically having a finned heat sink sandwiched between two plates, with DC power driving the Peltier effect between the plates. As an active device, the thermoelectric conduction device may be made to function compactly and economically, however, power consumption is generally required on an order of amps at digital electronics voltages (3.3 VDC, 5 VDC) which is outside of the range of battery-driven applications.
Heat pipes are often found with liquid cooling systems, where the heat pipes provide passive fluid conduction. Heat pipes are often bulky and fragile unless embedded in a substrate, which is generally impractical for confined spaces.
Extruded/bonded fin heat sinks are the most common type of thermal management device, which sometimes uses an attached fan. Generally the fin configuration of these devices occupies too much physical volume to be practical in extremely confined spaces. The conventional fin arrays, because of their jagged shapes, frequently cause turbulent air patterns that unevenly cool parts of the heat sink and the device to which it attaches.
Several patents have addressed the use of heat sinks. U.S. Pat. No. 5,146,981 (Samarov) discloses a heat sink with a plurality of holes, however, these holes appear to be haphazardly placed within the heat sink and are covered at one end. U.S. Pat. No. 5,552,634 (Schneider) discloses a heat sink with a plurality of pegs that may form multiple layers. U.S. Pat. Nos. 5,814,536 and 5,869,891 (Rostoker et al.) disclose a heat sink with fins, holes, protrusions, and grooves or depressions to increase the surface area of the fins of a heat sink. U.S. Pat. No. 5734552 (Krein) discloses an inverted airfoil configuration for a heat sink, however, the disclosed airfoil does not use holes for heat dissipation. None of these references discloses a maximized surface area with holes for heat transfer into and away from the heat sink.
There is a need in the art to provide a compact, thermally conductive system for electronic systems. The present invention addresses this and other needs.
The present invention includes a compact perforated heat sink having high heat dissipation consisting essentially of at least one substrate forming a plurality of holes therein, wherein the surface area of the substrate with the holes is equal to or greater than the surface area of the substrate without the holes, wherein heat flows through the holes, and means for thermal conductivity attached to the substrate capable of conducting heat away from a heat source into the substrate.
The invention further includes a perforated heat sink, in the shape of an airfoil, having high heat dissipation consisting essentially of at least one substrate having a first side and second side forming an airfoil having a leading edge and trailing edge, the substrate forming a plurality of holes therein, wherein the surface area of the substrate with the holes is equal to or greater than the surface area of the substrate without the holes, wherein heat flows through the holes, and means for thermal conductivity attached to the at least one substrate capable of conducting heat from a heat source to the at least one substrate and means for creating a substantially unidirectional fluid flow onto the leading edge, wherein lift is created within the plurality of holes.
Additionally, the present invention includes a method for dissipating heat from an electronic component, comprising the step of providing a compact perforated heat sink having high heat dissipation consisting essentially of at least one substrate forming a plurality of holes therein, wherein the surface area of the substrate with the holes is equal to or greater than the surface area of the substrate without the holes, wherein heat flows through the holes, and means for thermal conductivity attached to the at least one substrate capable of conducting heat from a heat source to the at least one substrate and conducting heat into the substrate through the means for thermal conductivity wherein the heat dissipates through the holes.
Furthermore, the present invention includes a dissipated heat product formed by the process comprising the steps of providing a compact perforated heat sink having high heat dissipation consisting essentially of at least one substrate forming a plurality of holes therein, wherein the surface area of the substrate with the holes is equal to or greater than the surface area of the substrate without the holes, wherein heat flows through the holes, and means for thermal conductivity attached to the at least one substrate capable of conducting heat from a heat source to the at least one substrate and conducting heat into the substrate through the means for thermal conductivity wherein the heat dissipates through the holes.
A composite heat sink may be formed from a plurality of compact perforated heat sinks, such as in a stacked formation including thermally conductive standoffs. The compact heat sinks may be used in any appropriate device, and are particularly useful in electronics systems.